Q66.2 Congenital metatarsus (primus) varus

Name of the Condition

• Congenital Metatarsus (Primus) Varus

Summary

Congenital metatarsus (primus) varus is a structural foot deformity present at birth characterized by an inward deviation of the first metatarsal bone, leading to misalignment of the forefoot. This condition may affect foot function and gait, with potential for cosmetic or functional concerns as the child grows.

Causes

The exact cause is not fully understood, but it is believed to involve a combination of genetic factors and disruptions during fetal development. Abnormalities in bone or soft tissue development may contribute to the deformity.

Risk Factors

• Family history of congenital foot deformities
• Intrauterine positioning (e.g., limited space, breech presentation)
• Maternal health conditions during pregnancy
• Prematurity or low birth weight

Symptoms

• Visible inward deviation of the first metatarsal at birth
• Altered forefoot alignment (e.g., inward or upward positioning)
• Limited range of motion in the foot or toes
• Difficulty fitting standard footwear as the child grows

Diagnosis

Physical examination by a healthcare provider to assess forefoot alignment and metatarsal positioning. Imaging studies (e.g., X-rays) may be used to evaluate bone structure in older children. Prenatal ultrasound may detect certain deformities before birth in some cases.

Treatment Options

• Observation for mild cases
• Orthotic devices or bracing to correct alignment
• Physical therapy to improve flexibility and strength
• Surgical intervention in severe or persistent cases to realign bones or soft tissues

Prognosis and Follow-Up

With early intervention, many children achieve normal foot function and alignment. Regular follow-up appointments are essential to monitor growth and adjust treatment as needed. Long-term outcomes depend on the severity of the deformity and adherence to treatment plans.

Complications

• Persistent foot misalignment affecting gait
• Difficulty with footwear or physical activity
• Increased risk of secondary musculoskeletal issues (e.g., ankle or knee strain)
• Potential for cosmetic concerns

Lifestyle & Prevention

• Regular monitoring of foot development in infants
• Use of supportive footwear as recommended by a healthcare provider
• Avoidance of restrictive footwear that may exacerbate deformities
• Engagement in age-appropriate physical activity to support foot strength

When to Seek Professional Help

• Visible foot deformity at birth or during infancy
• Difficulty with walking or balance as the child grows
• Pain or discomfort in the foot or ankle
• Concerns about footwear fit or foot alignment

Tips for Medical Coders

Document the specific anatomical deviation (e.g., inward metatarsal alignment) and any associated clinical findings. Ensure the diagnosis is clearly supported by physical examination or imaging results. Include details about treatment approaches (e.g., orthotics, surgery) if relevant to the encounter.